1. Field of Invention
The present invention relates to processes and devices for determining rheological properties of biological and other liquids. More specifically, the present invention is directed towards processes and devices for obtaining bodily mucus, chiefly cervical mucus and/or oral mucus, and for determining its viscoelastic properties in order to predict and indicate the inception and the presence of ovulation for conception control.
2. Description of the Prior Art
It has been found that mucus samples from the vaginal and oral cavities undergo distinct in-phase rheological changes during the menstrual cycle. Although the changes in the cervical mucus are much more noticeable than the changes in the oral mucus, both changes are readily determinable. During the immediate preovulatory phase under estrogen domination for a period of one to three days, the mucus is profuse and watery. During the postovulatory phase, under progestation, the mucus becomes less abundant and highly viscous. In healthy women with normal menstrual cycles, as is well documented in the medical literature, ovulation usually occurs between the 12th and 14th day prior to the next menstrual period. Specifically, cervical mucus is most hydrated (97 to 98 percent water) at the time of ovulation and is relatively dehydrated (80 to 90 percent water) at other times. The solid residue present after desiccation may range from 2 percent during ovulation to 20 percent at other times, a ten fold increase. Determining ovulation on the basis of the preceeding menstrual period, such as in the rythm method of counting the days ellapsed between the termination of the menstrual period and the presumed midcycle ovulatory phase, is prone to errors because of the great variability in the length of the proliferative period, i.e. between the end of the menses and ovulation. Although it is possible to predict ovulation on the basis of hormonal changes in the blood or chemical changes in the mucus, present procedures for such analyses besides being lengthly and costly, do not provide immediate result. In consequence, these procedures are utilized only in special cases. At present, there are no known reliable on-the-spot techniques that are capable of providing the information necessary for prediction or confirmation of ovulation during or immediately following examination of a patient.